Update the list of watchers and stargazers when clicking watch/unwatch or star/unstar (#32570)

We make sure the user cards are updated

- Fixes https://github.com/go-gitea/gitea/issues/32561

I also removed `ctx.Data["PageIsWatchers"] = true` and
`ctx.Data["PageIsStargazers"] = true` as they are not used anywhere.

# Before

![before](https://github.com/user-attachments/assets/e3bc3235-35eb-4eda-862d-bdf2510282ea)

# After

![after](https://github.com/user-attachments/assets/bc0488a5-8399-4cf6-95c9-17328a9702eb)

---------

Signed-off-by: Yarden Shoham <git@yardenshoham.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>

routers/web/repo/view.go

@@ -1123,8 +1123,6 @@ func RenderUserCards(ctx *context.Context, total int, getter func(opts db.ListOp
 func Watchers(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.watchers")
 	ctx.Data["CardsTitle"] = ctx.Tr("repo.watchers")
-	ctx.Data["PageIsWatchers"] = true
-
 	RenderUserCards(ctx, ctx.Repo.Repository.NumWatches, func(opts db.ListOptions) ([]*user_model.User, error) {
 		return repo_model.GetRepoWatchers(ctx, ctx.Repo.Repository.ID, opts)
 	}, tplWatchers)
@@ -1134,7 +1132,6 @@ func Watchers(ctx *context.Context) {
 func Stars(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("repo.stargazers")
 	ctx.Data["CardsTitle"] = ctx.Tr("repo.stargazers")
-	ctx.Data["PageIsStargazers"] = true
 	RenderUserCards(ctx, ctx.Repo.Repository.NumStars, func(opts db.ListOptions) ([]*user_model.User, error) {
 		return repo_model.GetStargazers(ctx, ctx.Repo.Repository, opts)
 	}, tplWatchers)